Rusty Holes!

Boyo

Active member
 Caerdydd
I had genuine BMW discs and pads fitted front and rear on my Z4MR approximately 3 months ago. The holes in the rear discs have developed some surface rust and I can't seem to remove it. The front discs have what looks like rusty water on the surface nearest near the centre of the discs where the pads don't reach. Again I can't remove this. I think the fault is mine in that I tend to wash the car (often) and then leave it stand. I have tried some sharp braking but no luck. Please does anyone have any suggestions.
 
Mine go rust almost straight away when the air is moist or it's wet, but the shine up straight away after braking and stay that way until it's moist again. The whole disk is shiny, no areas of rust.

Stick a picture up so we can see what you mean!
 
Boyo said:
I had genuine BMW discs and pads fitted front and rear on my Z4MR approximately 3 months ago. The holes in the rear discs have developed some surface rust and I can't seem to remove it. The front discs have what looks like rusty water on the surface nearest near the centre of the discs where the pads don't reach. Again I can't remove this. I think the fault is mine in that I tend to wash the car (often) and then leave it stand. I have tried some sharp braking but no luck. Please does anyone have any suggestions.

When you say the "holes" have surface rust - do you mean rust actually in the cross drilled holes? If so that is just life I am afraid - nothing will touch it so it won't get cleaned in normal use. However, if it is that the holes are actually clogging up with brake dust then you should clean it out - easiest is a cordless drill with a suitable slightly undersize drill bit. Jack the rear up with the handbrake off (chock the front wheels of course), remove the wheel and drill out each hole in turn.

Cross-drilled discs are the work of the devil really.
 
Sorry I didnt describe the issue with the front discs very well. The discs don't have an unswept area, Its merely a very narrow line of rusty water residue approximately 2mm wide running around the discs nearest their centre. The rear discs have light rust forming within the recessed lip of the drilled holes. Will try the cordless drill with attachment on the rears thanks. Anybody any suggestions on a suitable product to remove the rusty residue on the front discs. Will aim to post some pictures in the next couple of days.
 
Sandpaper or a decent file, it'll rub off no problem, in fact wire wool may shift it.

For the holes get yourself to B&Q, pick up a long series drill bit and a file handle and make yourself a little tool, the rust comes off easily by hand and the long series drill saves taking wheels off... :thumbsup:
 
Just a quick update - I used Fast Etch this morning and it very quickly eliminated the rust in the drilled holes together with the rusty residue on the front discs. The discs look as new. Many thanks to everyone for their responses :D
 
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